Hi Pamela,
I'm sorry to her about your loss of your sweet angel
Can you have another visit with your doctor and possibly have a few betas drawn to see what they're doing? Perhaps an u/s as well to make sure everything is ok inside of you or see what is going on... I wouldn't hesitate getting a check up or call your ob/gyn nurse triage to ask questions then see what they suggest to do.
It could be residual or it could be new pg, Is there a possibility like bd'ing w/ no protection?